The purpose of this proposal is to develop a portable automatic control system for the intra-aortic balloon pump. The system will be designed to provide maximum improvement in the energetics of the failing cardiovascular system. The concept is to furnish, during assistance, an optimal balance between the increase in oxygen availability to the myocardium and the decrease in its oxygen consumption. The system will be designed to function with minimal operator intervention, and to continuously adjust to changes in the patient's heart rate and status of the cardiovascular system.